The invention relates to a drive coupling for the coupling of an adjustment shaft with the ratchet adjusting knob of a watch, especially a wristwatch which includes a slide bushing axially movably disposed on the adjustment shaft and provided with a collar having axially projecting cams and detent structures.
Such watch operating mechanisms are well-known in the prior art.
The manufacture of the slide bushings with such drive couplings is quite difficult; particularly because the parts are so small. It is noted that the slide bushing must be provided with a non-circular central opening and also it must be cut on a lathe to form the collar and the engagement structure for an operating fork. Finally, milling operations are required to form the pawl structure projecting from the collar. The manufacture of such slide bushings and of the associated drive coupling is therefore quite involved and relatively expensive.
It is the object of the present invention to provide slide bushings with drive couplings which are easier and therefore less expensive to manufacture.